Mario Schlosser: Top 40 Healthcare Transformers

It was impossible to miss the ads. During the open-enrollment period for health insurance at the end of last year, mass-transit riders in the New York/New Jersey corridor found nearly every available flat surface papered with sly spots for Oscar Health ("Get a bright, articulate doctor to call you without having to join a dating site"). The insurance start-up snared 17,000 customers during its launch year and has its sights on far more. The hook? Customer service and readily comprehensible verbiage delivered via the tech devices embraced by younger consumers.

"Oscar was born out of the Affordable Care Act and the frustration people had with the health-insurance industry," says Schlosser, who co-founded the company with Josh Kushner and Kevin Nazemi. "We opened one of our own insurance bills only to realize we could not make any sense of it. We saw this as an opportunity to simplify this complicated industry, which can so often be overwhelming and unfriendly for consumers."